Rename tawashi to duckbin.

The library that used to be "tawashi_implem" now
is simply called tawashi.

src/tawashi_implem/ip_utils.hpp

@@ -1,29 +0,0 @@
-/* Copyright 2017, Michele Santullo
- * This file is part of "tawashi".
- *
- * "tawashi" is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * "tawashi" is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with "tawashi".  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#pragma once
-
-#include "duckhandy/compatibility.h"
-#include <string>
-
-namespace tawashi {
-	namespace cgi {
-		class Env;
-	} //namespace cgi
-
-	std::string guess_real_remote_ip (const cgi::Env& parCgiEnv) a_pure;
-} //namespace tawashi